Saturday, 4 April 2015

The most recent update of the U.S. Geologic Survey earthquake hazard maps shows a big bull’s-eye over the Bootheel. But the agency says there’s no reason to panic. “We don’t know that an earthquake is imminent — we can’t predict earthquakes. But we do expect the past behavior in the New Madrid region to be a representation of how things might happen,” said Robert Williams, Central and Eastern U.S. regional coordinator for the USGS in Golden, Colorado. “This is a ground motion hazard map, not a map showing the expectation of where earthquakes will actually hit,” Williams said. The map shows there’s a 2 percent chance over the next 50 years the area will exceed 80 percent of the acceleration of gravity. The USGS builds its earthquake hazard maps for engineers based on quakes that have occurred, Williams said. “But it’s estimating the chance of exceeding ground motions in the next 50 years.” Williams said the 50-year period is a common engineering design time interval for the life of a building. “Obviously you have to have an earthquake to get the ground motions, but doesn’t try to say exactly where the earthquakes are going to occur and when they’ll happen, just an estimate of future ground motions.” FULL REPORT